Прогнозирование состояния железобетонных трубопроводов, находящихся под автомобильными дорогами

In this paper offered a new method for forecasting the condition of reinforced concrete pipelines, which are located under the roads. It has a practical value in the absence of special diagnostic equipments and robotics.Предложена новая методика прогнозирования состояния железобетонных трубопроводов, находящихся под автомобильными дорогами. Это имеет практическое значение при отсутствии специального диагностического оборудования и робототехники

ВЛИЯНИЕ КОНСТРУКЦИИ ПРОЗРАЧНОГО ПОКРЫТИЯ НА ЭФФЕКТИВНОСТЬ ТЕРМООБРАБОТКИ БЕТОНА В ОПАЛУБОЧНЫХ ФОРМАХ С ИСПОЛЬЗОВАНИЕМ СОЛНЕЧНОЙ ЭНЕРГИИ

The shuttering forms, equipped by inventory frames with transparent cover, are the simple solar energy equipment for heat treatment of reinforced concrete elements during their manufacturing at the plants. They are similar with solar collectors by their design and thermal-physical processes, taking place in them, with difference that the heat sink is hardening concrete. The research results of influence of transparent cover construction on efficiency of concrete heat treatment in shuttering forms with employment of solar energy in different climatic conditions are given in the article. The volume of energy, consumed and lost by concrete during its direct heating by solar energy in the simple solar energy equipment like solar collector, depends on the transparent cover construction. Under other same conditions, the increase of cover layers affects its transparency, which is characterized by the solar energy transmittance, but in this case, it reduces heat losses in environment, which are characterized by the coefficient of heat losses through transparent cover. One-layer and two-layer transparent covers are chosen for assessment of efficiency of heat treatment of concrete elements, because the increase of cover layers more than two reduces intensity of the heat sink warming in the daytime and it is accepted by scientists in solar energy field as pointless. Optimal number of transparent material layers in cover construction is determined based on energy assessment in result of thermal- physical calculation and experimental research. The economic losses for production of transparent cover due to the increase of its layers are taken into account in addition with energy assessmentОпалубочные формы, оснащенные инвентарными рамами с прозрачным покрытием, являются простейшими гелиотехническими устройствами для тепловой обработки железобетонных изделий при производстве их на полигонах при заводах ЖБИ. По своему конструктивному решению и теплофизическим процессам, протекающим в них, они схожи с солнечными коллекторами, с разницей в том, что теплоприемником является твердеющий бетон. В статье приведены результаты исследований влияния конструкции прозрачного покрытия на эффективность термообработки бетона в опалубочных формах при использовании солнечной энергии в различных климатических условиях. Количество теплоты, поглощенное и потерянное бетоном при прямом нагреве его солнечной энергией в простейших гелиотехнических устройствах типа плоского коллектора, зависит от конструкции прозрачного покрытия. При прочих равных условиях, увеличение количества слоев покрытия негативно влияет на его прозрачность, характеризующуюся коэффициентом пропускания солнечной энергии, но при этом снижает тепловые потери в окружающую среду, характеризующиеся коэффициентом тепловых потерь через прозрачное ограждение. Для оценки эффективности тепловой обработки железобетонных изделий выбраны однослойное и двухслойное прозрачные покрытия, так как увеличение слоев больше двух снижает интенсивность нагрева теплоприемника в дневное время суток и признано учеными в области гелиотехники нецелесообразным. На основе энергетической оценки в результате теплофизических расчетов и экспериментальных исследований выявлено оптимальное количество слоев прозрачного материала в конструкции покрытия. Помимо энергетической оценки, учтены экономические затраты на изготовление конструкции прозрачного покрытия при увеличении его слоев

Совершенствование технологии возведения фундаментов в вытрамбованных котлованах и устройство для ее реализации

Uniform and periodic covering of a surface rammer a layer of a lubricity liquid for reduction of friction of the soil and prevent soil from adhering to surface rammer produced by the spongy plate established in a cavity of the guide trunk and impregnated with lubricity liquid.Равномерное и периодическое покрытие поверхности трамбовки слоем смазывающей жидкости для снижения трения о грунт и предотвращения налипания грунта к поверхности трамбовки производят посредством губчатой пластины, установленной в полости направляющего ствола и пропитанной смазывающей жидкостью (вода, отработанное машинное масло, дизельное топливо и пр.)

Техническое состояние инфраструктурных систем жизнеобеспечения городов Ирака и показатели их надежности

Maintenance, inspection and repair of drainage pipes are characterised by increased responsibility for their technical condition and quality of work. This allows more efficient use of economic, logistical and human resources in the maintenance of pipelines.Эксплуатация, обследование и ремонт трубопроводов водоотведения характеризуются повышением ответственности за их техническое состояние и качество выполняемых работ. Это дает возможность более эффективно использовать экономические, материально-технические и трудовые ресурсы при эксплуатации трубопроводов

Influence of Formwork Structure on Heat Treatment of Precast Concrete Elements by Solar Energy

The present paper aims to study the influence of the formwork structure on the efficiency of heat treatment (HT) of precast concrete elements (PCE) by solar energy in various climatic conditions. The objects of the study were different types of formworks composed of solar energy equipment for HT of PCE. In total, six types of formworks, made of steel sheet, laminated plywood and timber, with and without insulation were studied. Calculation and experimental study were carried out for humid continental, and subtropical climates. Experimental study was carried out in the laboratory and in the open air. According to the obtained results, the heat insulation material in the formwork structure contributes to increase the strength of concrete. Formwork with heat insulation layer of 40 mm gave the best results. However, the level of the contribution depends on climatic conditions. Heat insulation material in the formwork structure is necessary in humid continental climate. Even the thickness of the insulation layer of 20 mm gives good results and the difference between the concrete strength with thickness of 20 mm and 40 mm is insignificant. On the contrary, in humid subtropical climate, the heat insulation material in the formwork structure is favorable, but not compulsory, since the difference between the concrete strengths is not significant and the strength values, obtained in all six types of formwork, allow it to be removed after 24 hours of curing

Физико-механические свойства базальто-волокнистого высокопрочного бетона

Relevance. Basalt fibers are increasingly studied in structural applications due to its environmental friendliness, good mechanical properties, thermal and chemical resistance. The aim of work. Mass production of high-strength concrete in Russia is mostly associated with the use of organomineral modifiers of the MB series, which consist of composition microsilica, fly ash, hardening regulator and superplasticizer C-3 in various proportions. The purpose of the experimental research is to study the effect of basalt fibers in high-strength concrete. Solution technique. The research of physical and mechanical properties of basalt-fibered high-strength concrete was made on samples with detentions of 100×100×100 and 100×100×400 mm with the use of modifier MB10-30C. The compressive strength, the tensile strength at bending, the strength at axial tension, and the cracking moment in various periods of curing (after 7, 14, 28 and 60 days of curing) were determined under the research. Results. The research results show that the use of basalt fibers in high-strength concrete resulted in a decrease in the compressive strength about 18-20 %, however, enhance the tensile behavior about 42-48 %.Актуальность. Базальтовые волокна все чаще изучаются для применения в промышленном и гражданском строительстве благодаря хорошим механическим свойствам, термической и химической стойкости, а также экологичности. Цель. Массовое производство высокопрочного бетона в России во многом связано с применением органоминеральных модификаторов серии МБ, содержащих в разных пропорциях микрокремнезем, золу-уноса, регулятор твердения и суперпластификатор С-3. Целью экспериментального исследования является изучение влияния базальтовых волокон в высокопрочном бетоне. Методы. Исследования физико-механических свойств базальто-волокнистого высокопрочного бетона проведены на образцах с размерами 100×100×100 и 100×100×400 мм с применением модификатора МБ10-30С. В рамках исследования определены: прочность на сжатие, прочность на растяжение при изгибе, прочность на осевое растяжение и момент трещинообразования в различные периоды твердения бетона (после 7, 14, 28 и 60 суток твердения). Выводы. Исследования показали, что добавление базальтовой фибры в высокопрочный бетон снижает прочность на сжатие на 18-20 %, однако позволяет повысить его поведение при растяжении на 42-48 %

Editorial Preface

The present proceedings include a selection of papers submitted to the International Conference on Engineering Systems 2020 (ICES 2020), which was held during 14-16 October 2020 in the RUDN University, Moscow, Russia.ICES 2020 was dedicated to the 60th anniversary of RUDN University. International Conference on Engineering Systems (ICES), held annually at the Peoples’ Friendship University of Russia (RUDN University), has created a platform for summarizing research in various areas of engineering. The aim of the conference is to foster and conduct collaborative interdisciplinary research amongst the researchers, professionals and industrialists to share their research experiences and indulge in interactive discussions and special sessions at the event.In light of travel restrictions around the world to control COVID-19 pademic, ICES 2020 adopted the format of virtual conference through Google Meet network to provide a forum for experts and scholars to share real-time information and discuss the latest findings on various engineering fields. The conference included keynote speech and online discussion, and each presenter has 20–25 minutes (including Q&A).With the full support from the International Scientific Committee, all submissions have been through rigorous review and process to meet the requirements of international publication standard. Accepted papers were presented in five sessions of the conference: 1) Fundamental Engineering, 2) Civil and Structural Engineering, 3) Mechanical Engineering, 4) Composite Materials, 5) Hydraulic and Geological Engineering. We hope that this collection will be useful for many specialists and researchers from various engineering fields.List of Conference Chair, Conference secretary, International Scientific Committee and Guest Editors are available in this pdf

Effect of gelatin powder, almond shell, and recycled aggregates on chemical and mechanical properties of conventional concrete

The objective of the research is to study the effect of different additives on the conventional concrete. In this term, three types of materials have been added to the concrete: gelatin powder as the binder, recycled aggregates, and almond shell as the fine and coarse aggregates. Several experiments have been made tо determine physical and mechanical properties, such as test for compressive and tensile strengths, for impact loading strength, durability test (water absorption) and deep penetration tests. Moreover, the microstructure results for the new type of concrete have been studied by means of scanning electron microscopy (SEM) and energy-dispersive x-ray spectroscopy (EDXS). The results show that when 70 kg of gelatin powder is added to 1 m3 of concrete, the concrete’s compressive strength and tensile strength are improved more than 22%; during impact loading the first and ultimate cracks are 11 and 129 by numbers, and the first and ultimate cracks’ strength is more than 223 and 2346 J respectively. The durability of sample from concrete with additional gelatin has been improved. SEM results illustrate that the weakness of almond shell concrete is related to cracks and voids between the cement matrix and almond shell. The voids of gelatin concrete are higher than that of conventional concrete. The conventional concrete has smooth crystals, and gelatin concrete has sharp and cubic crystals. EDXS results show that chemical content of these two types of concrete is different: conventional concrete contains silicon, while EDXS results show that chemical content of these two types of concrete is different: conventional concrete contains silicon, while gelatin concrete contains calcium and also C-S-H gel is generated in it

Forecasting the condition of reinforced concrete pipelines, located under the roads

In this paper offered a new method for forecasting the condition of reinforced concrete pipelines, which are located under the roads. It has a practical value in the absence of special diagnostic equipments and robotics

Perfecting of technology of Foundation Construction in a Rammed Pit

Uniform and periodic covering of a surface rammer a layer of a lubricity liquid for reduction of friction of the soil and prevent soil from adhering to surface rammer produced by the spongy plate established in a cavity of the guide trunk and impregnated with lubricity liquid